Decreasing compositions



United States Patent Ofiice 3,123,566 Patented Mar. 3, 1964 3,123,566 DEGREASING COMPUSITIONS Walter E. Kramer, Niles, and Louis A. J00, Crystal Lake, 13]., assignors to The Pure Oil Company, Chicago, 111.,

a corporation of Ohio No Drawing. Filed Dec. 30, 1960, Ser. No. 79,543 23 Claims. (Cl. 252139) 1 weight, aromatic, alkylaromatic, and heterocyclic diand polybasic acids derived from solvent extracts obtained in the manufacture of mineral lubricating oils.

Degreasing compositions containing Various ingredients and combinations are known in the prior art. Many of these metal degreasing formulations incorporate solvents such as butanol, butyl Cellosolve, kerosine, etc., to increase their oil-solubilizing and emulsifying abilities. These solvents not only increase the cost, but also contribute to the hazards of use of the formulations because of the danger of fire and the emission of noxious vapors. In addition, the oil-solubility characteristics are often deficient for todays degreasing problems, requiring several applications of the solvent or the use of temperatures above room temperature.

This invention is based on the discovery that metal salts of complex, polynuclear, high-molecular-weight, aromatic, alkylaromatic, and heterocyclic diand polycarboxylic acids derived from solvent extracts obtained in the solvent refining of mineral lubricating oils have the ability to dissolve or emulsify at least about 12% of their weight of oil or grease to form a clear solution and the cleansing action is superior to conventional degreasing compositions. A feature of this invention is the discovery that aqueous solutions containing about to 70% by weight of said metal salts of complex acids are capable of solubilizing at least 12% of their weight of oil, and the resulting solution remains clear even at this high oil content.

Another feature of this invention is the discovery that the metal salts of said complex polycarboxylic acids may 3 used without the benefit of the various solvents used in conventional degreasing formulations. Furthermore, the metal salts of complex polycarboxylic acids are compatible with and are enhanced 'by various softeners, complexing agents, saponifying agents, and extenders to form degreasing formulations which are superior to the conventional solvent-containing compositions of the prior art and may be used as aqueous solutions.

It becomes then a primary object of this invention to provide novel and effective degreasing formulations containing effective amounts of metal salts of complex polynuclear, high-molecular-weight, aromatic, alkylaromatic, and heterocyclic diand polycarboxylic acids derived from solvent extracts.

Another object of this invention is to provide aqueous degreasing formulations containing about 10% to 70% by weight of said metal salts of complex polycarboxylic acids derived from solvent extracts.

A further object of this invention is to provide degreasing formulations, which are devoid of conventional solvents, containing said metal salts of complex polycarboxylic acids derived from solvent extracts along with one or more extenders, saponifying agents, softeners and complexing agents.

An object of this invention is to provide degreasing formulations containing about 20% to by weight of alkali metal salts of complex polycarboxylic acids derived from solvent extracts or without one or more extenders, saponifying agents, softeners and] or complexing agents.

Another object of this invention is to provide aqueous degreasing formulations containing about 20% to 65 by weight of metal salts of said complex polycarboxylic acids, about 10 to 25% by weight of an alkali metal polyphosphate, about 10% to 35% by weight of an alkali metal metasilicate, about 10% to 20% by weight of an alkali metal carbonate, and from 0% to about 15% by weight of an alkali metal phosphate.

Still another object of this invention is to provide aqueous degreasing formulations containing 2 to 10 oz. per gallon of a composition containing about 20% to 65 by weight of alkali metal salts of complex polycarboxylic acids derived from solvent extracts with or without one or more or all of the extenders, saponifying agents, softeners and/or complexing agents disclosed herein.

Another object of this invention is to provide aqueous solutions of the foregoing formulation at concentrations of about 2-10 oz. per gallon for use in soak-cleaning and spray-cleaning operations in the degreasing of metals, concrete, tile, ceramics, sewer-traps, cess-pools, and any other applications where the ability to dissolve oils or grease finds utility.

These and further objects of this invention will be described or become apparent as the specification proceeds.

The main ingredient of the degreasing formulations of this invention, namely the metal salts of complex polynuclear, high-molecular-weight, aromatic, alkylaromatic, and heterocyclic diand polycarboxylic acids, is prepared from solvent extracts and other sources of said complex nuclei by applying the methods of several copending applications by the instant inventors and others, wherein the solvent extracts are reacted with an alkali metal under metalation conditions, and then are treated with carbon dioxide under carbonation conditions to form the alkali metal salts of the resulting diand polycarboxylic acid which are separated from the unreacted oil and are ready for use. The methods described in application Serial Number 819,932, filed June 12, 1959, now abandoned, and application Serial Number 79,661, filed December 30, 1960, may be used in the preparation of the free acids or their salts for incorporation into the formulations of this invention, and the description of the methods, the starting materials, and the characteristics of the acids or their salts set forth in said copending applications are hereby incorporated by reference. Consequently a description of the starting material, and a brief description of the preparation of the acids and their salts, along with some ex amples, is sufficient for purposes of adequate disclosure herein.

The starting material for the reaction may be any complex polynuclear, aromatic and/or heterocyclic hydrocarbon from synthetic or natural sources. A preferred and unique source of aromatic starting material comprises petroleum fractions rich in the more complex, polynuclear, aromatic hydrocarbons, not only because the dibasic or polybasic acid products therefrom have unique properties, but also because the salts thereof are particularly adapted to the formulation of effective degrcasing compositions in accordance with this invention. Illustrating the preferred and novel starting materials is the class known as solvent extracts from the manufacture of mineral lubricating oils, which solvent extracts are rich in complex, polynuclear, aryl, alkaryl, condensed ring and heterocyclic nuclei forming the organic portion of the dibasic or polybasic carboxylic acids of this invention. Solvent extracts from the manufacture of bright stock and neutral lubricating oils are particular examples of such fractions rich in complex aromatic compounds obtained as by-products from the solvent refining of mineral oils.

For example, a preferred source of the above-defined complex hydrocarbons comprises the extracts obtained in solvent-refining mineral oils, particularly lubri cating oil fractions. These extracts, hereinafter referred to as solvent extracts, are obtained as the extract or solvent phase when lubricating oils are refined by treatment with a selective solvent having an afiinity for aromatic and sulfur compounds. The complex hydrocarbons removed by this refining treatment often contain appreciable amounts of combined sulfur, nitrogen, and oxy- 'gen. These complex hydrocarbons contain a predominance of polynuclear rings of aromatic structure, and of condensed configurations having or containing hydrocarbon substituent groups attached thereto as side chains. These starting materials are generally of a viscous nature, have low viscosity indices, low resistance to oxidation, and are considered to be deleterious in lubricating oils. Heretofore, these aromatic extracts have been regarded as waste products, and because they are exceedingly complicated mixtures of complex compounds, including various sulfur-, oxygen-, and nitrogen-containing compounds, they have not been used successfully in preparing petrochemicals or as sources of hydrocarbon reactants or starting materials.

The starting materials used are adequately described as those aromatic materials separated from mineral lubricating oils and their fractions i.e., those aromatics obtained in the manufacture and refining of neutral oils and bright stocks during treatment with a selective solventdesigned to extract the predominantly aromatic materials from the parafifinic materials. Solventextracts resulting from the treatment of mineral lubricating oils for the purpose of separating non-aromatic hydrocarbons (the ra'fiinate and finished oil) from the aromatic hydrocarbons (the extract and waste product) may be used and are preferred as starting materials.

Since the general process of refining mineral lubricating oils in which solvent extracts are obtained is Well known, it is only necessary for present purposes to describe a typical procedure for obtaining same and give some examples by way of illustration.

In a typical operation, desalted crude oil is first charged to a distiilation unit where straight-run gasoline, two grades of naphtha, kerosine, and virgin distillate are taken off, leaving a reduced crude residue. The reduced crude is continuously charged to a vacuum distillation unit where three lubricating oil distillates are taken off as side streams, a light distillate is taken ofi as overhead, and a residuum is withdrawn from the bottom of the tower. The residuum is charged to a propanedeasphalting unit wherein propane dissolves the desirable lubricating oil constituents and leaves the asphaltic materials. A typical vacuum residutun charge to the propane-deasphalting unit may have an API gravity of l2.9, viscosity SUS at 210 F. of 1249, flash 585 F., fire 650" F., C.R. of 13.9 weight percent, and may be black in color. The deasphalted oil may have an API gravity of 215 to 21.8, viscosity SUS at 210 F. of 165-175, NPA color 67, flash 575 F., fire 650 F., and C.R. of 1.7-2.0. The deasphalted oil and various lubricating oil distillates from the reduced crude are subjected to solvent extraction for the separation of non-aromatic from aromatic constituents prior to use. The refined oil or raffinate from the extraction processes is used per se, or as blending stock, for lubricating oils, and the solvent extract, predominating in complex aromatic constituents, is distinctively useful in accordance with this invention.

For example, a crude oil from an East Texas field, with an API gravity of 33.1 was topped to remove such light fractions as gasoline, naphtha, kerosine and a light lubricating distillate. The vacuum residue was a reduced crude, having a viscosity of 1251 SUS at 210 F., 2.2 percent sulfur, and an API gravity of 12.6". After propane-deasphalting, the oil had a viscosity of 174 SUS at 210 F., and an API gravity of 21.7". This deasphalted oil was treated with phenol to produce a rafiinate from which an aviation lubricating oil could be prepared. The oil extracted by phenol treatment, after removal of phenol, is ready for use as the starting material to prepare the acids, and salts for use in accordance with this invention.

Solvents other than phenol may be used to obtain the extraction product used in accordance with this invention, for example, liquid sulfur dioxide, nitrobenzene, Chlorex (trademark for proprietary 2,2-dichloroethylether), chlorophenol, trichloroethylene, cresylic acid, pyridine, furfural, or the Duo-Sol solution (comprising liquid propane and cresol) may be used. When using phenol, it is possible to vary the characteristics of the extract and raflinate products considerably by adjustment of the amount of water present. A rafiinate of relatively low viscosity index can be obtained by using a water solution of phenol during the extraction, and a rafiinate of high viscosity index can be obtained by using anhydrous phenol. Following are the physical characteristics of typical extract products, from lubricating oil stocks dei rived from various crude oils and other source hydrocarbon materials, which may be used.

TABLE 1 Sources and Physzcal Characterzstlcs by Solvent Extracts Ext. API Sp. Vis./ Vls./ Vis./ F. F. Iodine Per- Per- No. Crude Source Solvent Grav. Gr. at F. F 210 F. V.I. Pour Flash Fire No. cent cent 10 F. (Wijs) Sulfur Springs.

Texas Furfural 13.0

Chlorex 12.2

Nitr0henzene 10.0

Propanecres0l 14.4

TABLE ICont1nued Sp. Iodine Per- Per- Ext. Crude Source Solvent API Gr. at Vis./ Vis./ Vis. V.I. Pour F. F. No. cent cent No. Grav. F. 100 F. 130 F 210 F Flash Fire (Wiis) 0.R. Sulfur Phenol 13. 6 41. 7 82 13.6 200 --61 55 1.1 2. 75 80 41 11 0.1 2.0 26,000 5, 615 360 5. 5 2. 3 ,054 331 61.5 -56 0.4 2. 7 2, 007 611 71.1 -128 0.86 3. 2 East Tex 230, 000 20, 800 796 76 7. 7 3.0

N orns:

Extract No. 41 was obtained in the production of 85 VI neutral, had an average molecular weight of 300, and contained 76.8% aromatics (by the silica gel procedure).

Extract No. 42 was obtained in the production of 150 VI Bright Sto 14% saturates, 86.2% carbon, 11.4% hydrogen, and averaged 3.3 aromatic rings per aromatic molecule.

Extract No. 43 was obtained in the production of 170 VI neutral, saturates, 86.4% carbon, 10.7% hydrogen and averaged 2.7 aromatic rings per aromatic molecule.

Extract No. 44 was obtained in the production of 200 VI neutral, had an average molecular weight of 340, contained 87% saturates had an average molecular Weight of 340, contained 84.1%

ck, had an average molecular Weight of 590, and contained 86% aromatics,

aromatics, 15.9%

aromatics, and 13% Extract N o. 45 was obtained in the production of 160 VI Bright Stock, contained 92% aromatics and 8% saturates.

TABLE II Range of value 09446-10195. 35o 25,o00 (ext).

Characteristic Gravity, API

Gravity, spc., 60/ 60 Viscosity SUS 100 F TABLE I11 t S 130 F 140-19,000. viscosi y Us o Estimated Chemical Composition of Solvent Extracts Nos. Viscosity SUS 210 F 200 1500. Viscosity index O1. +39 and f Table 1 g gg 3 5 Type of compound: gfi giigi in 1 '"T 1 Saturated hydrocarbons 12 5 Mo ecu average 320 750 Mononuclear aromatics: Substituted benzenes 25.0 gfiggg i 6 Dinuclear aromatics: Substituted naphthalenes- 30.0

Trinuclear aromatics: gg gi gg gz g F T Substituted phenanthrenes 10.0 Substituted anthnacenes 5.0 g compounds Percent by Tetranuclear aromatics:

"7 Substituted chrysenes 00.5 g gg i 2313 compounds 90 Substituted benzphenanthrenes 0.2 Substituted pyrenes 0.2 Thlo compounds percent by 1440 Pentenuclear aromatics: Perylene 0.01 v01 50 Sulfur compounds oxygen compounds etc. 16.5

Neutral aromatic hydrocarbons. 40-51. Av. No. of rings/means aron.

mol 1.7-3.5. H/C wt. ratio 0.116-013'6. H/ C atom ratio, whole sample 1.383-1.622. H/C atom ratio, aromatic portion 1289-1500.

Nearest empirical formula C H -C H The specific gravities of the extracts in general increase with increase in the viscosity of the raifinate at a constant viscosity index. Stated otherwise, the specific gravities of these extracts increase With decrease in viscosity index of the raffinate at a constant viscosity. For the production of 100:5 VI neutral oils, the viscosities of the extracts increase with increase in stated viscosities of the neutral oils (raifinates). The pour points of extracts are high and are affected by changes in the depth of extraction. The sulfur contents are also afiected by the depth of extraction. The solvent extracts are characterized by containing aromatic and heterocyclic compounds in the range of 75-98%, the remainder being principally saturates, or material behaving as saturates, together with a minor proportion of up to about 7% of organic acids. The organic acids present are not susceptible to extraction by the use of aqueous strong caustic because of the solubility Mainly heterocyclic compounds. The average mol. wt. of Extracts 19 and 21 is 340, and that .of Extract 20 is 590.

Any portion of the reactive aromatic constituents in solvent extracts may be isolated therefrom, or from other sources, to be used as starting materials to prepare the polybasic acid salts used in the formulations of this invention. For example, solvent extracts may be distilled and selected fractions thereof used as the starting materials. The content of reactive, complex, polynuclear, aromatic compounds and heterocyclics present in solvent extracts, as illustrating the preferred source material, may vary depending on the type of solvent, the extraction process applied, and the mineral oil treated, although the general types of compounds present in the extract are not so varied. Extracts containing from about 20% to of polynuclear aromatics and heterocyclics of aromatic nature represent a preferred type of starting material.

In addition to the general physical and chemical properties of the solvent extracts given in Tables II and III, these starting materials may be further characterized by the fact that their average molecular Weight is about 300 to 750, the boiling point (initial) is between 300 to 1000" F., the end boiling point is between 400 to 1200 F., and they may exhibit pour points as high as 100 F. Chemically, the extracts may contain 1.9 to 4.5% wt. of sulfur,

exhibit a H/C wt. ratio of 0.116 to 0.136, a H/C atom ratio of 1.383 to 1.622, a H/C atom ratio, based only on the aromatic portion, of 1.289 to 1.500, and the nearest empirical formula is C I-I to 044E156. The extracts may contain from about 15% to 50% by volume of sulfur compounds, and'30% to 90% by volume of aromatic and thio' compounds.

The aromatic nuclei are alkyl-substituted and heterocyclic-substituted naphalene, phenanthrene and anthracene configurations in which the sum of the carbon atoms in the alkyl substituents varies from 15 to 22 and the heterocyclic substituents contain sulfur, oxygen and nitrogen or combinations thereof. About 52% dehydronaphaline type acids, 40% dehydrophenanthrene type acids and 8% dehydroanthracene type acids are present in the mixture. The molecular weight range of the acids is 325 to 450 and may be as high as 750 and the acids contain at least 2 to as many as 4 carboxyl groups. Typical acids have acid numbers of 200 to 280, melting points of 80 to 90 C., bromine numbers of 16 to 215, contain 1.7 to 2.16 wt. percent sulfur, are deep red in color, transparent in thin sheets and contain 2 to 6% unsaponifiables. The acids are soluble in ethyl ether, acetone, methyl ethyl ketone, tetrahydrofuran, benzene, toluene and xylene. Many of these characteristics, particularly the chemical characteristics, carry over into the degreasing formulations of this invention.

One procedure is to react about 30 parts of a petroleum fraction rich in complex polynuclcar aromatics, as exemplified by solvent extracts, with 1 to parts of an alkali metal, including sodium, potassium, cesium, lithium and rubidium, and their mixtures and amalgarns, at a temperature of about 60 to 80 C. in the presence of a reaction solvent such as dimethyl glycol ether, dimethylether, methylalkyl ethers, dialkyl glycol ethers, tetrahydrofuran, methyl ethyl ketone, methylal, and trimethylamine. The formation of the adduct is promoted by shearing, agitation, providing an excess of alkali metal, using a preformed dispersion-of the alkali metal in an inert solvent, or using a pre-formed dispersion of the alkali metal in a portion or all of the solvent extract. These techniques overcome the induction period of the reaction due to impurities, including the sulfur compounds present therein, which tend to coat the alkali metal particles and prevent the reaction or prolong the induction period. A Brookfield counter-rotating stirrer is used to give continuous shearing and expose fresh metal surfaces during the reaction. Color changes indicate the progress of the reaction.

The alkali metal adduct thus formed is either separated or left in the unreacted oil and the mixture is treated with excess gaseous or solid carbon dioxide at temperatures ranging from about 20 C. to 80 C., causing a discharge of the color. This forms the alkali metal salt of the complex acid which, upon acidification with a mineral acid, yields the desired complex, polynuclear, polycarboxylic acids in good yields. To illustrate, the following non-limiting examples are given.

EXAMPLE I One hundred grams Extract No. 19, from the preparation of 170 vis., 100 VI neutral oil, dissolved in 675 cc. of dry tetrahydrofuran was reacted with agitation at 10 to 30 C. with 8.3 gms. of metallic sodium in the form of A cubes. After 25 minutes, adduct-formation began and a strong color change took place. The product was cooled to 60 C. while an excess of carbon dioxide gas was introduced, resulting in a discharge of the color without precipitation. Then 5.1 gms. of unreacted sodium was removed, the tetrahydrofuran was vacuum-stripped, and the remaining liquid combined with ether and waterwashed. Acidification of the aqueous phase and further ether washing resulted in the recovery of free acids. About 11% of the solvent extract had reacted. The acid product had an indicated average molecular weight of 686, a neutralization number of 171, and a calculated equivalent weight of 328, indicating 2.1 carboxyl groups per molecule.

EXAMPLE II One hundred grams of Extract No. 19 and 675 ml. of dry tetrahydrofuran were charged to a one-liter, 3-necked flask equipped with a stirrer, thermometer, pressure-equal ized drop-funnel, gas inlet with rotometer and gas outlet. A dry nitrogen atmosphere was maintained in the flask. Approximately gms. of alundum balls, in diameter, were charged and agitation started. The solution was cooled to 20 C. and 8.3 gms. of sodium as a 20% dispersion in toluene were added. After an induction period of about 5 minutes, the solution was warmed and at 7 C. the reaction began; in 17 minutes it was proceeding rapidly. An excess of dry carbon dioxide was added at C. over a period of 78 minutes. The reaction mass was worked up as in Example I after the excess sodium was destroyed with water. About 15% of the phenol extract reacted and 22.5 gms. of acid were recovered having a neutralization number of 241, indicating an equivalent weight of 233. The acid product contained 2.8% sulfur.

EXAMPLE III The process of Example II was repeated producing complex acids having a neutralization number of 323, indicated equivalent weight of 173, and an indicated average molecular weight (cryoscopic) of 600, and containing 3.0% sulfur. The ratio of molecular weight to equivalent weight was 3.4, indicating a mixture containing acids with more than two carboxyl groups per molecule.

EXAMPLE IV The various recovered acids of application Serial Number 819,932 illustrated in Table II therein are further examples of polycarboxylic acids to be used to prepare the formulations of this invention.

EXAMPLE V The various polycarboxylic acid products described in runs 12 through 47 of application Serial Number 79,661, are further examples of acids that may be used.

The salts formed during the carbonation treatments described in the foregoing examples may be used, after separation from the unreacted oil, in preparing the degreasing formulations of this invention. The step of acidification allows the production of the free complex polycarboxylic acids from which the alkali metal salts may be prepared for use herein. The alkali metals intended herein include sodium, potassium, lithium, rubidiurn and cesium and the salts are either obtained in situ in the preparation of the complex acids after the carbonation step or prepared from the purified complex acids or impure complex acids by metathesis reactions.

To illustrate the effectiveness of the degreasing formulations of this invention, the following non-limiting examples are given.

EXAMPLE VI An aqueous solution of extract dibasic acid was prepared, as described in Example I, by reacting Extract No. 44 with metallic sodium, reacting the resulting product with carbon dioxide, and washing the mixture with water. The aqueous solution was found to be capable of solubilizing at least 12% w. of its weight of oil, the solution remaining clear even at this high oil content. This ability is far superior to that of conventional cleansing compounds which only solubilize up to 5% of oil.

EXAMPLE VII A specific type of degreasing and cleansing formulation, containing salts of extract dibasic acids in accordance with this invention, has the following composition:

Constituent: Percent wt. Sodium salt of extract dibasic acids 2065 Sodium tripolyphosphate 1 10-25 Sodium metasilicate 10-35 Sodium carbonate 3 10-20 Trisodium phosphate 15 1 Softener and complexing agent.

11 Dirt suspension aid and *saponitying agent.

3 Inexpensive extender,

4 sapon ifying agent.

Aqueous solutions of this formulation, at concentrations of about 2-10 oz. per gallon, are effective when used in soak and spray-cleaning operations for degreasing metals, without the use of auxiliary organic solvents.

EXAMPLE VIII An aqueous solution of potassium salts of the complex polycarboxylic acids prepared in accordance with Example 111 is prepared by reacting 500 g. of the acids With an excess of potassium hydroxide at 100 C. The aqueous solution is adjusted to a concentration of about 25% by weight of said salts, and 15% by weight of potassium tripolyphosphate, 30% by weight of potassium metasilicate, and 30% by weight of potassium carbonate are incorporated.

EXAMPLE X The lithium salts of the complex polycarboxylic acids of Example I are prepared by reaction of about 100 g. of said acids with an excess of lithium hydroxide. The aqueous solution containing a concentration of about 65% of said lithium salts is a good degreasing formulation.

The following are additional examples of formulations coming within the definition of this invention.

TABLE IV Degreasing Formulations 10 extenders, saponifying agents, softeners and/ or complexing agents.

The formulations may be adjusted in accordance with the cost of the ingredients and other known ingredients may be included. Sodium sulfate can be used in place of sodium carbonate and the latter can be the commercial form known as soda ash. Similarly alkali metal pyrophosphates can be used in place of the alkali metal tripoly phosphate salts. Although the formulations have been found to work well without the known prior art solvents such as butanol, butyl Cellosolve, kerosine and the like, these are not excluded from the compositions.

The formulations of this invention find application in degreasing and cleaning various stamped, milled, lathed, forged and otherwise processed metal parts in the metalfabricating industry in preparation for later processing steps, such as electroplating, phosphatizing, painting or enameling or porcelainizing. These cleaning operations take the form of vapor-degreasing, soak-cleaning or spraycleaning. Because the soak-cleaning or spray-cleaning processes are not all capable of removing heavy oils or greases from metal parts the vapor-degreasing process is commonly used, despite the potential hazards and vapor losses. Attempts have been made to overcome the inelfectiveness of the soakand spray cleaning process by use of hydrocarbon solvents or coupling agents to increase the oil-holding properties of the formulations. However, this practice is expensive, hazardous and not always effective. The formulations of this invention have such increased oil-holding properties as to make them effective when used in :soakand spray-cleaning operations for degreasing metals without the necessity of resorting to solvents or using the more dangerous and costly vapordegreasing processes.

Other examples of feed materials that comprise a source of related polynuclear aromatic compounds from which the alkali metal salts of polycarboxylic acids may be derived are FCC recycle stock and combined reformate polymers described in copending application Serial Number 79,661.

The embodiments of the invention, in which an exclusive property or privilege is claimed, are defined as follows:

1. A degreasing composition consisting essentially of an aqueous solution of about 10% to about by weight of alkali metal salts of complex polynuclear aromatic heterocyclic diand p-olycarboxylic acids derived Polybasie Tripoly Phos- Metasilicate Carbonate Salt Phosphate Salt Acid Salt phate Salt Salt Composition N o.

Oonc., Oonc., Oonc., Oonc., Type Cone. Type Percent Type Percent Type Percent Type Percent wt. wt. wt. wt.

20-65 K 10-25 Li 10-35 Cs 10-20 Rh 0-15 20-65 Li 10-25 Cs 10-35 Rb 10-20 Na 0-15 20-65 Cs 10-25 Rb 10-35 Na 10-20 K 0-15 20-65 Rb 10-25 Na 10-35 K 10-20 Li 0-15 25 Na 10 K 30 Li 20 CS 15 55 K 15 K 10 K 15 K 5 53 Li 15 Li 10 Li 15 Li 7 58 Cs 10 Us 15 Us 15 Cs 2 50 Rb 12 Rb 15 Rb 15 Rb 8 50 K 10 Na 10 K 20 N a 10 20-65 Na 80-35 20-65 Na 80-35 20-65 Na 80-35 20-65 Li 10 Rb 15-55 Na 15 20-65 Na. 10 K 25-70 20-65 K 10-30 K 0-60 K 5-10 As seen from the foregoing non-limiting examples, including those in Table IV, the invention is directed to degreasing formulations containing alkali metal salts of complex, polynuclear, high-molecular-weight, aromatic, alkylarornatic, heterocyclic diand polycarboxylic acids derived from solvent extracts, with or without various from solvent extracts, obtained in the solvent extraction of mineral lubricating oils with a solvent selective for aromatic compounds, by metalation of said solvent extracts to form the alkali metal adduct, carbonation of said adduct to form the alkali metal salt of the corresponding carboxylic acid, acidification of said salt to form the free acid and reaction of said acid with a basic compound having a cation corresponding to the finished product, characterized by having an average molecular weight of about 320 to 750, containing about 1.9 to about 4.5% by weight of combined sulfur and having about 1.7 to 3.5 average number of aromatic rings per mean aromatic molecule.

2.; A degreasing composition in accordance with claim 1 in which the concentration of said alkali metal salts of said complex acids is about 20% to about 65% by weight.

3. A degreasing composition in accordance with claim 1 in which said alkali metal salts are sodium salts.

4. A degreasing composition in accordance with claim 1 in which said alkali metal salts are potassium salts.

5. A degreasing composition in accordance with claim 1 in which said alkali metal salts are cesium salts.

6. A degreasing composition in accordance with claim 1 in which said alkali metal salts are lithium salts.

7. A degreasing composition in accordance with claim 1 in which said alkali metal salts are rubidium salts.

8. A degreasing composition consisting essentially of an aqueous solution of the composition of claim 1 having a concentration of about 2 to 10 oz. of said composition per gallon.

9. A degreasing composition consisting essentially of an aqueous solution of about 20% to about 65% by weight of alkali metal salts of complex polynuclear aromatic heterocyclic diand polycarboxylic acids derived from solvent extracts, obtained in the solvent extraction of mineral lubricating oils with a solvent selective for aromatic compounds, by metalation of said solvent extracts to form the alkali metal adduct, carbonation of said adduct to form the alkali metal salt of the corresponding carboxylic acid, acidification of said salt to form the free acid and reaction of said acid with a basic compound having a cation corresponding to the finished product, characterized by having an average molecular weight of about 320' to 750, containing about 1.9 to about 4.5% by weight of combined sulfur and having about 1.7 to 3.5 average number of aromatic rings per mean aromatic molecule and up to about 80% by weight of at least one alkali metal salt of the group consisting of alkali metal tripolyphosphate, alkali metal metasilicate, alkali metal carbonate and alkali metal phosphate.

10. A degreasing composition consisting essentially of an aqueous solution of the composition of claim 9 having a concentration of about 2 to 10 oz. of said composition per gallon.

11. A degreasing composition in accordance with claim 9 containing about 10% to about 25% by weight of said alkali metal tripolyphosphate, about 10% to about 35% by weight of said alkali metal metasilicate, about 10% to about 20% by weight of said alkali metal carbonate and to about 15% by weight of said alkali metal phosphate.

12. A degreasing composition consisting essentially 'of an aqueous solution of about to about 70% by weight of the sodium salts of complex polynuclear aromatic heterocyclic carboxylic acids derived from phenol extract obtained in the phenol extraction of mineral lubricating oils, said complex acids being characterized by being mixtures of acids containing about 2 to 4 carboxyl groups per molecule, having an average molecular weight of about 320 to 750, containing about 1.9 to about 4.5%

by weight of combined sulfur and having about 1.7 to 3.5 average number of aromatic rings per mean aromatic molecule.

13. A degreasing composition in accordance with claim 12 in which the concentration of said sodium salts of said complex acids is about 20% to about 65% by weight.

14. A degreasing composition in accordance with claim 12 in which said complex acids are characterized by a neutralization number of about 171 and are primarily dibasic.

15. A degreasing composition in accordance with claim 12 in which said complex acids are characterized by a neutralization number of about 241 and contain about 2.8% by weight of combined sulfur.

16. A degreasing composition in accordance with claim 12 in which said complex acids are characterized by having a neutralization number of about 323, contain about 3.0% by weight of combined sulfur and are primarily dibasic.

17. A degreasing composition in accordance with claim 12 containing about 10% to about 25% by weight of said alkali metal tripolyphosphate, about 10% to about 35% by weight of said alkali metal metasilicate, about 10% to about 20% by weight of said alkali metal carbonate and 0% to about 15 by weight of said alkali metal phosphate.

18. A degreasing composition in accordance with claim 12 in which the concentration of said sodium salts of said complex acids is about 20% to by weight and containing about 10% to about 25% by weight of sodium tripolyphosphate, about 10% to about 35% by weight of sodium metasilicate, about 10% to about 20% by weight of sodium carbonate and 0% to about 15 by weight of trisodium phosphate.

19. A degreasing composition consisting essentially of an aqueous solution of the composition of claim 17 having a concentration of about 2 to 10 oz. of said composition per gallon.

20. A degreasing composition consisting essentially of an aqueous solution of about 20% to about 65% by weight of a salt of the group consisting of sodium, potassium and lithium salts 'of complex polynuclear aromatic heterocyclic carboxylic acids prepared by reacting phenol extract obtained in the phenol extraction of mineral lu-- bricating oils with sodium in the presence of tetrahydrofuran at a temperature of about -20 to C. to form the sodium adduct, reacting said adduct with an excess of carbon dioxide at a temperature of about C. to form the sodium salts of the corresponding mixed carboxylic acids, removing unreacted sodium, distilling the liquid reaction mass to remove the tetrahydrofuran, dissolving the remaining liquid in ether, water-washing said ether solution, recovering the aqueous phases soproduced, acidifying the combined aqueous phases to recover the purified free complex acids and converting said acids to said salts by reaction with an hydroxide of the metal corresponding to the finished product.

21. A degreasing composition in accordance with claim 20 containing about 20% by weight of said sodium salts of complex carboxylic acids and about 25% by weight of sodium carbonate.

22. A degreasing composition in accordance with claim 20 containing about 25% by Weight of said potassium salts of complex carboxylic acids, about 15 by weight of potassium tripolyphosphate, about 30% by weight of potassium metasilicate.

23. A degreasing composition in accordance with claim 20 containing about 65 by weight of lithium salts of complex carboxylic acids.

References Cited in the file of this patent UNITED STATES PATENTS 1,707,031 Stuart Mar. 26, 1929 2,279,001 Math'eson et al. Apr. 7, 1942 2,961,410 Martin Nov. 22, 1960 2,988,560 Schmerlung et a1 June 13, 1961 2,992,992 Curtin July 18, 1961 

1. A DEGREASING COMPOSITION CONSISTING ESSENTIALLY OF AN AQUEOUS SOLUTION OF ABOUT 10% TO ABOUT 70% BY WEIGHT OF ALKALI METAL SALTS OF COMPLEX POLYNUCLEAR AROMATIC HETEROCYCLIC DI- AND POLYCARBOXYLIC ACIDS DERIVED FROM SOLVENT EXTRACTS, OBTAINED IN THE SOLVENT EXTRACTION OF MINERAL LUBRICATING OILS WITH A SOLVENT SELECTIVE FOR AROMATIC COMPOUNDS, BY METALATION OF SAID SOLVENT EXTRACTS TO FORM THE ALKALI METAL ADDUCT, CARBONATION OF SAID ADDUCT TO FORM THE ALKALI METAL SALT OF THE CORRESPONDING CARBOXYLIC ACID, ACIDIFICATION OF SAID SALT TO FORM THE FREE ACID AND REACTION OF SAID ACID WITH A BASIC COMPOUND HAVING A CATION CORRESPONDING TO THE FINISHED PRODUCT, CHARACTERIZED BY HAVING AN AVERAGE MOLECULAR WEIGHT OF ABOUT 320 TO 750, CONTAINING ABOUT 1.9 TO ABOUT 4.5% BY WEIGHT OF COMBINED SULFUR AND HAVING ABOUT 1.7 TO 3.5 AVERAGE NUMBER OF AROMATIC RINGS PER MEAN AROMATIC MOLECULE. 